A Highly Efficient and Robust Perovskite Anode with Iron-Palladium Co-exsolutions for Intermediate-Temperature Solid-Oxide Fuel Cells.

The low performance and insufficient catalytic activity of perovskite anodes hinder their further application in intermediate-temperature solid-oxide fuel cells (IT-SOFCs). A novel La Sr Fe Nb Pd O (LSFNP) anode material has been developed with Fe-Pd co-exsolutions for IT-SOFCs. Fe and Pd metallic nanoparticles are confirmed to exsolve on the surface of the perovskite anode during operation under a hydrogen atmosphere. The introduced Pd exsolutions promote the charge-transfer process slightly and the H -adsorption ability of the La Sr Fe Nb O (LSFN) parent anode significantly, as metallic Pd is a conductor with excellent catalytic activity and an absorber of hydrogen that can absorb a large amount of H by forming unstable chemical bonds. A single cell with the LSFNP anode exhibits high output performance (maximum power density of 287.6 mW cm at T=800 °C by using humidified H as the fuel), excellent redox stability, and considerable coking and sulfur tolerances. After the introduction of Pd exsolutions, the increase in the electrochemical performance is more significant under low H concentrations and at low temperatures with a maximum power density ratio of the LSFNP anode cell/LSFN anode cell reaching 18 under 5 % H /argon at T=650 °C. Pd-decorated LSFNP is a high-performance, redox-stable, coking-tolerant, and sulfur-tolerant anode material for IT-SOFCs, making Pd exsolution a reliable nanodecoration strategy to improve the low kinetics of perovskite anodes.